Colorado River and Associated Lakes and Reservoirs (Lake Havasu Dam to Imperial Dam)
2026 303(d) list Waterbody ID CAR7151000020080709112211 River & Stream Region 7 · Colorado River
At a glance
- 2026 listing Evidence: State-published
- On the 2026 303(d) list · 3 Appendix A decisions
- Category 5: a TMDL is required
- What a listing means
- Pollutants and stressors
- 3 pollutants in 3 Appendix A categories
- Pesticides (1) · Sediment (1) · Total Toxics (1)
- Listing decisions
- TMDL information Evidence: State-published
- 3 decisions with a TMDL requirement status
- Status codes as published: 5A
- TMDL details
- Industrial stormwater facilities
- 0 report it as their receiving water Evidence: identification corroborated
- 1 within 1 km Evidence: geographic proximity
- Neither count establishes a discharge · Facilities
What a 303(d) listing means
The Clean Water Act section 303(d) list names waters that do not meet water quality standards for one or more pollutants or stressors. California publishes it in the Integrated Report; this page shows the 2026 decisions from Appendix A as published.
- A listing describes the condition of the waterbody. It does not identify which sources cause the impairment, and it does not by itself place a requirement on any particular facility.
- Listed waters do not all have the same status. The Integrated Report category says how an impairment is being addressed: 5, a TMDL is required; 4a, addressed by a USEPA-approved TMDL; 4b, addressed by other pollution control requirements; 4c, impairment not caused by a pollutant. This waterbody's decisions are in category 5.
- TMDL requirement status values (such as 5A or 5B) are shown exactly as published in Appendix A.
2026 listing status Evidence: State-published
- On the 2026 303(d) list
- Yes
- Appendix A decisions
- 3
- Integrated Report category
- 5 (a TMDL is required)
- Listing cycle
- 2026
- State Board adoption
- 2026-02-03 (Resolution 2026-0005)
- USEPA approval
- not confirmed — submittal letter to USEPA published; no approval found on the report page (checked 2026-10-22)
- Regional Water Board
- 7 — Colorado River
Published by the State Water Resources Control Board (2026 California Integrated Report, Appendix A). Listing status is taken from Appendix A only. A listing describes the condition of this waterbody, not of any facility.
Location
Loading the waterbody shape…
Open this area on the statewide map · Browse impaired waters
Listing decisions and pollutants Evidence: State-published
Grouped by the Pollutant Category published in Appendix A. Pollutant names, categories and decisions are exactly as published.
Pesticides (1 decision)
| Pollutant | Pollutant category | Category | Final listing decision | Decision status | Sources | Decision ID |
|---|---|---|---|---|---|---|
| DDT (Dichlorodiphenyltrichloroethane) | Pesticides | 5 | Do Not Delist from 303(d) list (TMDL required list) | Revised | A Source Unknown | 170121 |
Sediment (1 decision)
| Pollutant | Pollutant category | Category | Final listing decision | Decision status | Sources | Decision ID |
|---|---|---|---|---|---|---|
| Turbidity | Sediment | 5 | Do Not Delist from 303(d) list (TMDL required list) | Revised | A Source Unknown | 159289 |
Total Toxics (1 decision)
| Pollutant | Pollutant category | Category | Final listing decision | Decision status | Sources | Decision ID |
|---|---|---|---|---|---|---|
| Toxicity | Total Toxics | 5 | Do Not Delist from 303(d) list (TMDL required list) | Revised | A Source Unknown | 77980 |
TMDL information Evidence: State-published
| Pollutant | TMDL requirement status | TMDL project | Priority | USEPA approval of TMDL | Expected attainment |
|---|---|---|---|---|---|
| DDT (Dichlorodiphenyltrichloroethane) | 5A | — | Low | — | — |
| Toxicity | 5A | — | Low | — | — |
| Turbidity | 5A | — | Low | — | — |
This is TMDL information for the waterbody. It does not establish that a TMDL applies to any particular facility. Facility-specific TMDL requirements recorded in SMARTS appear on facility pages and are not linked to this waterbody until reviewed.
HUC12 watersheds
Published with the listing Evidence: publisher-reported
- Gene Wash-Colorado River 150301010713
- Giers Wash-Colorado River 150301040104
- Bowmans Wash-Colorado River 150301040105
- Bennett Wash-Colorado River 150301040108
- Town of Earp-Colorado River 150301040301
- Arch Creek-Colorado River 150301040304
- Lost Lake-Colorado River 150301040306
- 150301040403-Colorado River 150301040403
- Slaughter Tree Wash-Colorado River 150301040404
- Palo Verde Dam-Colorado River 150301040406
The published list is truncated in Appendix A; it is not a complete list of watersheds.
Overlapping the waterbody's shape Evidence: spatial
- Gene Wash-Colorado River 150301010713 also published
- Giers Wash-Colorado River 150301040104 also published
- Bowmans Wash-Colorado River 150301040105 also published
- Bennett Wash-Colorado River 150301040108 also published
- Town of Earp-Colorado River 150301040301 also published
- Arch Creek-Colorado River 150301040304 also published
- Lost Lake-Colorado River 150301040306 also published
- 150301040403-Colorado River 150301040403 also published
- Slaughter Tree Wash-Colorado River 150301040404 also published
- Palo Verde Dam-Colorado River 150301040406 also published
- Town of Ehrenberg-Colorado River 150301040609
- Petes Wash-Colorado River 150301040705
- Cibola Lake-Colorado River 150301041107
- Turnaround Wash-Colorado River 150301041203
- Carrizo Wash-Colorado River 150301041205
- Marcus Wash-Colorado River 150301041208
- Ferguson Wash-Colorado River 150301041308
- Imperial Reservoir-Colorado River 150301041311
Industrial stormwater facilities
Evidence: identification corroborated
Shows: the facility named this waterbody as its receiving water in SMARTS, and the name and the facility's location are consistent with it. Does not establish: a discharge pathway, a discharge of any pollutant, or a cause of the listing.
Evidence: geographic proximity
Shows: the facility's reported location is within 1 km of the waterbody's mapped shape. Does not establish: that the facility discharges to this waterbody, or any other relationship.
Report this waterbody as their receiving water Evidence: identification corroborated
No facility's reported receiving water is identified as this waterbody.
Within 1 km of a facility's reported location Evidence: geographic proximity
Spatial proximity only; discharge pathway not established. Being near this waterbody does not mean a facility discharges to it.
| Facility | WDID | Status | Distance | Map |
|---|---|---|---|---|
| Toms Quarry | 7 33I021917 | Terminated | 397 m | map |
1 facility, nearest first.
Sources and provenance
| Information | Source | Retrieved |
|---|---|---|
| Watershed Boundary Dataset HU2 GeoPackages 15, 16, 18 (WBDHU12) | USGS | 2026-10-22 |
| 2026 California Integrated Report, Appendix A: 2026 303(d) List (final) | SWRCB | 2026-10-22 |
| Final_2026_Rivers_and_Streams + Final_2026_Lakes_and_Reservoirs (FeatureServer 0) | SWRCB GIS | 2026-10-22 |
| SMARTS TMDL requirements | SMARTS | 2026-10-21 |
Relationships computed 2026-10-22 (facility_huc12/1, proximity/1, receiving_water/2, tmdl_reference/1, waterbody_huc12_ovl/1, waterbody_huc12_pub/1).
Integrated Report categories: 5, a TMDL is required; 4a, addressed by a USEPA-approved TMDL; 4b, addressed by other pollution control requirements; 4c, impairment not caused by a pollutant.